UNCLASSIFIED
Avian Influenza Daily Digest
December 10, 2008 23:30 GMT
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60-Day HPAI H5N1 Outbreak Map
2008 WHO Confirmed Human Cases HPAI H5N1
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Quid Novi
Thailand: Five Suspected Bird Flu Patients Found in Surin Province
South Korea: LPAI tests Positive for Migratory Birds, Negative at Poultry Farms
India: Bird flu hits more areas of Assam
WHO: Cumulative Number Human Cases of H5N1
Hong Kong begins mass cull of birds at market, screens virus
Regional Reporting and Surveillance
Azerbaijan: Bird Flu Monitoring
12/10/08 Azeri Press, contributed by email--The State Veterinary Service of Azerbaijan will monitor bird flu situation in the country.
Regional Reporting and Surveillance
Spain: Update on HPAI reported in 2006
12/10/08 7th Space--The H5N1 strain of avian influenza virus has been involved in severe mortality in domestic poultry, and has also been found in different species of wildlife in Europe. The Basque Country avian influenza surveillance program began sample collection and processing the fall of 2005.
Regional Reporting and Surveillance
Hong Kong: Time has come to fix failing bird flu defences
12/10/08 South China Morning Post, contributed by email--Our city's elaborate defences against bird flu have, once again, been breached. This time, dead chickens at a farm in Yuen Long have been confirmed to be infected by the H5 virus. The government must move swiftly to discover the source of the infection and review the system. It is clearly not working as well as it should do.
Regional Reporting and Surveillance
Germany: LPAI reported at Turkey Farm
12/10/08 ARGUS--Regional media report the detection of low pathogenic avian influenza at a turkey farm in Cloppenburg district. According to Niedersachsen?s Ministry of Agriculture, all of the farm?s 9,000 birds have already been culled. A spokesperson for the Ministry speculates...
Regional Reporting and Surveillance
Indonesia reports 2 new H5N1 cases, 1 fatal
12/10/08 CIDRAP--The World Health Organization (WHO) today said that Indonesia's health ministry has notified it of two new human H5N1 avian influenza cases, a 9-year-old girl who has recovered and a 2-year-old girl who died.
Regional Reporting and Surveillance
Hong Kong Will Investigate Whether Bird Flu Vaccine Failed
12/10/08 Bloomberg--Hong Kong will check whether bird flu vaccines failed or the virus mutated, after an outbreak prompted the cull of more than 80,000 chickens.
Regional Reporting and Surveillance
Science and Technology
Antibody Persistence after 2-Dose Priming and Booster Response to a Third Dose of an Inactivated, Adjuvanted, Whole-Virion H5N1 Vaccine
12/10/08 Journal of Infectious Diseases [abstract]--An inactivated, alum-adjuvanted, whole-virion H5N1 vaccine had been evaluated previously. Hemagglutination inhibition (HI) assays showed that the antibody levels declined significantly, with 4.8%?20.8% and 0%?18.8% of participants retaining seroprotection (HI titer 1:40) 6 and 12 months after the second dose, respectively. A third dose of the same vaccine given 12 months after the second dose significantly boosted immune responses. Thirty days after the third dose in the 1.25-, 2.5-, 5-, and 10-?g dose groups, 29.4%, 31.3%, 78.6%, and 90.0% of participants had HI titers 1:40, and 52.9%, 81.2%, 92.9%, and 100% of participants had microneutralization titers 1:40, respectively. Both the 5-?g and 10-?g doses met European Union criteria.
Vaccines
Dressed to Kill: From Virus to Vaccine
12/11/08 Physorg.com--In a pioneering effort, researchers at the National Institute of Standards and Technology and the University of Queensland in Australia have successfully demonstrated that they can count, size and gauge the quality of virus-like particle-based (VLP) vaccines much more quickly and accurately than previously possible. Their findings could reduce the time it takes to produce a vaccine from months to weeks, allowing a much more agile and effective response to potential outbreaks.
Vaccines
Pandemic Preparedness
Economy puts emergency readiness in peril
12/10/08 USA Today-- The economic crisis is jeopardizing the nation's ability to handle public-health emergencies and possible bioterrorist attacks, according to government leaders and a new report. [full text link to report] Federal and state governments are cutting programs that help communities respond to disease outbreaks, natural disasters and bioterrorism incidents, and that "could lead to a disaster for the nation's disaster preparedness," a report released Tuesday warns.
Pandemic Preparedness
Full Text of Articles follow ...
Regional Reporting and Surveillance
Azerbaijan: Bird Flu Monitoring
12/10/08 Azeri Press, contributed by email--The State Veterinary Service of Azerbaijan will monitor bird flu situation in the country.
The next monitoring will start December 15 because of bird migration. The monitoring will cover the Apsheron Peninsula, national parks and reserves in the Devechi, Salyan, Agcabadi and Lenkaran regions, as well as nearshore zones.
The samples of poultry and wild animals will be submitted to the Republican Veterinary laboratory. The results will be announced December 26.
Prohibition of hunting, use and sale of migrating, wild birds in the country still remains in force.
Quid Novi
Thailand: Five Suspected Bird Flu Patients Found in Surin Province
12/10/08 Thailand Outlook--Surin Province has implemented measures against avian flu epidemic after five patients were recently discovered with bird flu-like symptoms.
Deputy Chief of Surin Public Health Office, Peerasak Polprueksa, has revealed that five patients are now under close watch as they are suspected of being infected with bird flu after handling poultry that died 7 to 14 days ago.
Two of the suspected bird flu patients are from Karb Cheong District, another two from Muang and Sanom districts, and one is Cambodian.
Residents in Surin Province are advised to clean their hands after handling poultry, to wear disposable masks, and cover their mouths with handkerchiefs when sniffing or coughing.
Meanwhile, officials of the Surin Livestock Department, the Animal Quarantine Office, and Kabcheong Public Office sprayed a disinfectant substance around fowl markets near the Chong Jom border that connects to Cambodia, to prevent an epidemic of bird flu.
Quid Novi
South Korea: LPAI tests Positive for Migratory Birds, Negative at Poultry Farms
12/10/08 ARGUS--Local, regional and national sources are reporting low pathogenic avian influenza, AI H5N2, detected in Hampyeong County, Cholla-namdo (Jeolla-namdo), in samples taken from a migratory bird population at a local reservoir. Announced on 10 December, the tests date from 4 December.
Sources report two poultry farms, raising a total of 66,000 chickens, ducks, and geese, are within 10 kilometers of the site. Samples taken from these two sites have so far come back negative for any type of AI. Testing is ongoing at both the reservoir and poultry farms.
Article URL(s)
http://www.ijejutoday.com/news/articleView.html?idxno=65103
http://news.mk.co.kr/newsRead.php?sc=30000017&cm=%EA%B8%B0%EC%97%85%C2%B7%EA%B2%BD%
EC%98%81%20%EC%A3%BC%EC%9A%94%EA%B8%B0%EC%82%AC&year=2008&no=749931&selFlag=&relatedcode=&wonNo=&s
ID=501
http://www.gwangnam.co.kr/read.php?idxno=2008121020265552909
Regional Reporting and Surveillance
Spain: Update on HPAI reported in 2006
12/10/08 7th Space--The H5N1 strain of avian influenza virus has been involved in severe mortality in domestic poultry, and has also been found in different species of wildlife in Europe. The Basque Country avian influenza surveillance program began sample collection and processing the fall of 2005.
Results: Here we report the first confirmation of the presence of highly pathogenic H5N1 strain in a Great Crested Grebe (Podiceps cristatus) found dead in a pond near Vitoria in the Basque Country on the North of Spain.
Regarding the survey for generic influenza type A virus, we have obtained positive results in about 8% of more that 3500 birds examined.
Conclusions: We think that the self-limiting nature of our finding and others proves that certain regions have ecological, geographical and climatological features that make it difficult for the H5N1 virus to spread [1] and cause disease at least in the large scale scenario that has been worrying human and animal health authorities during the last years.
Author: Marta Barral, Vega Alvarez, Ramon A. Juste, Inigo Agirre and Inaki Inchausti
Credits/Source: BMC Veterinary Research 2008, 4:50
Regional Reporting and Surveillance
Hong Kong: Time has come to fix failing bird flu defences
12/10/08 South China Morning Post, contributed by email--Our city's elaborate defences against bird flu have, once again, been breached. This time, dead chickens at a farm in Yuen Long have been confirmed to be infected by the H5 virus. The government must move swiftly to discover the source of the infection and review the system. It is clearly not working as well as it should do.
Most worrying is the discovery that chickens which had been vaccinated against the potentially deadly virus are among those infected. This would seem to confirm warnings sounded earlier in the year that the effectiveness of the vaccine, such an important component in our defences, is fading. Steps must be taken to ensure that, as far as possible, vaccines provide adequate protection.
There is a disturbing sense of déjà vu about the return of the bird flu virus. It was only in June that poultry at four wet markets were found to be infected, leading to the culling of thousands of birds. The latest outbreak is a reminder that we remain vulnerable, despite all the efforts that have been made to guard against the virus.
About 80,000 chickens at the affected farm and 10,000 more it had sent to a wholesale market will have been culled by today. The import and export of live chickens will be banned for three weeks. Retail and wholesale markets have been shut as workers start disinfecting facilities. These are necessary measures, but not long-term solutions.
It is too early to determine the extent of the outbreak. Inspectors are collecting and testing samples from other farms and markets. Hopefully, the latest incident is confined to the single farm known to be affected so far. Its owner is to be commended for speedily reporting the incident to the authorities. But, if it had involved a less responsible owner, detection would have taken much longer, and the virus would have had more time to spread.
The infection of vaccinated birds raises fresh concerns. Scientists who monitor the vaccination programme have been warning about its declining effectiveness. The government introduced vaccination at all local farms in 2003. University of Hong Kong microbiologists say we are not far from the day when the vaccines will become useless. Worse, they warn that some vaccinated chickens may not show symptoms and so spread the virus as "silent carriers". Hong Kong has been using the same vaccine for years. It is time to consider whether a change would improve prevention.
Bird flu is a deadly threat to public health. The surest way to contain it is to end the live poultry trade. Yet, despite the September buyout deadline the government imposed on traders, a significant minority of retailers, wholesalers and farmers have refused to trade in their licences. They will continue in business until the government introduces central slaughtering. Now that the government is pushing for more public works to create new jobs in this economic downturn, it should make building a central slaughtering facility a priority. The latest outbreak shows there is no time to waste.
Vaccines
Antibody Persistence after 2-Dose Priming and Booster Response to a Third Dose of an Inactivated, Adjuvanted, Whole-Virion H5N1 Vaccine
12/10/08 Journal of Infectious Diseases [abstract]--China-Japan Friendship Hospital, 2National Institute for the Control of Pharmaceuticals and Biological Products, 3Sinovac Biotech Ltd., and 4State Key Laboratory for Infectious Disease Prevention and Control, National Institute for Viral Disease Control and Prevention, 5Chinese Center for Disease Control and Prevention, Beijing, China
An inactivated, alum-adjuvanted, whole-virion H5N1 vaccine had been evaluated previously. Hemagglutination inhibition (HI) assays showed that the antibody levels declined significantly, with 4.8%?20.8% and 0%?18.8% of participants retaining seroprotection (HI titer 1:40) 6 and 12 months after the second dose, respectively. A third dose of the same vaccine given 12 months after the second dose significantly boosted immune responses. Thirty days after the third dose in the 1.25-, 2.5-, 5-, and 10-?g dose groups, 29.4%, 31.3%, 78.6%, and 90.0% of participants had HI titers 1:40, and 52.9%, 81.2%, 92.9%, and 100% of participants had microneutralization titers 1:40, respectively. Both the 5-?g and 10-?g doses met European Union criteria. (ClinicalTrials.gov identifier: NCT00660257.)
Received 15 May 2008; accepted 21 August 2008; electronically published 9 December 2008.
Reprints or correspondence: Dr. Wei-Dong Yin, 39 Shangdi Western Rd., Haidian District, Beijing (100085), China (yinweidong@sinovac.com); or, Dr. Zi-Jian Feng, 27 Nanwei Rd., Xuanwu District, Beijing (100050), China (zijianf@hotmail.com).
*
Potential conflicts of interest: W.-D.Y., J.-T.C., Y.-Z.Q., Y.L., and X.W. are employed by, and J.-T.L. has received research funding from, Sinovac Biotech. All other authors report no potential conflicts.
Financial support: Ministry of Science and Technology of the People's Republic of China (grant 2004BA519A66); Sinovac Biotech (research grant).
*
aJ.-T.L. and C.-G.L. contributed equally to this work.
Regional Reporting and Surveillance
Germany: LPAI reported at Turkey Farm
12/10/08 ARGUS--Regional media report the detection of low pathogenic avian influenza at a turkey farm in Cloppenburg district. According to Niedersachsen?s Ministry of Agriculture, all of the farm?s 9,000 birds have already been culled. A spokesperson for the Ministry speculates that wild birds are the source of contamination and added that there is no reason to worry since the detected strain is very mild. Authorities sealed off the area within a 1,000 meter [0.6 mile] radius of the affected farm and are currently disinfecting farms within this radius. The Ministry spokesperson stated that there are no suspected cases at other poultry farms.
Article URL(s)
http://www.hna.de/boulevardstart/00_20081210192000_Vogelgrippe_in_Mastbetrieb_im_Kreis_Cloppenbur.html
-Affected Areas:
CLOPPENBURG
Quid Novi
India: Bird flu hits more areas of Assam
12/11/08 Economic Times/India--More areas of Assam are coming under bird flu virus. Fresh cases of bird flu have been detected at Khanapara in Guwahati, Dikom area of Dibrugarh district in Upper Assam and Bejera area of Kamrup district.
Three districts of Assam, Kamrup, Nalbari and Barpeta district are witnessing the outbreak of HN51virus. Now two other districts of Kamrup (Metro) and Dibrugarh are witnessing the outbreak.
Sources in veterinary department said: ?Bird flu in a firm in Khanapara was confirmed after 30 birds perished in the last few days. The virus was also confirmed in the Dikom area in Dibrugarh district. The confirmation came after 300 chicks died recently. We will start culling operation of the birds in the farm from Thursday,? he said.
Sources in Kamrup metro district said sale and import of poultry and poultry products have been banned in the city.
?We have also put the health officials on alert to deal with health-related cases,? he said. In Dibrugarh about 40,000 birds will be culled. In Kamrup district, bird flu has been confirmed in Jalah village under Bejera area. Culling in Jalah will also start on Thursday, veterinary officials said.
Bird flu was also detected a Thakurchuba, Sarpara, Patgaon and Rampur under Kamrup district. Over three lakh birds are to be culled in the different districts.
Regional Reporting and Surveillance
Indonesia reports 2 new H5N1 cases, 1 fatal
12/10/08 CIDRAP--The World Health Organization (WHO) today said that Indonesia's health ministry has notified it of two new human H5N1 avian influenza cases, a 9-year-old girl who has recovered and a 2-year-old girl who died.
The announcements come as health officials from Indonesia and other nations are meeting in Geneva this week to work on an agreement for sharing H5N1 virus samples.
The WHO said the 9-year-old girl from Riau province got sick on Nov 7, was hospitalized 5 days later, and was released from the hospital on Nov 27.
Few other details were available about the girl's illness. The WHO said an investigation into the source of the girl's infection revealed poultry deaths on Nov 2 at her family's home.
In the second case, the 2-year-old girl who died was from East Jakarta. The WHO said the girl got sick on Nov 18, was hospitalized 8 days later, and died on Nov 29.
The WHO said initial investigations indicate that the girl may have been exposed to the virus at a live bird market.
The two cases bring Indonesia's H5N1 case count to 139, including 113 deaths.
Today's statement from the WHO didn't address previous media reports on the death of a 15-year-old girl from central Java who?according to a local medical official and a doctor who treated her?died of an H5N1 infection on Nov 7. However, on Nov 13 Indonesia's health minister, Siti Fadilah Supari, denied reports that the girl had H5N1 and said tests from two laboratories came back negative, according to previous reports.
Indonesia has been hit harder than any other country by the H5N1 virus. However, the country has stopped sharing H5N1 samples to protest the lack of access to and affordability of avian influenza vaccines and treatments.
Indonesia also said in June that it would no longer promptly report H5N1 cases and would give only periodic updates. The country released its last update in early September.
Today's announcement of the two new Indonesian cases raises the global H5N1 count to 389 cases and 246 deaths.
Quid Novi
WHO: Cumulative Number Human Cases of H5N1
Cumulative Number of Confirmed Human Cases of Avian Influenza A/(H5N1) Reported to WHO
Cases: 389
Deaths: 246
Quid Novi
WHO: Indonesia Update #45
Avian influenza ? situation in Indonesia ? update 45
9 December 2008 -- The Ministry of Health of Indonesia has announced two new confirmed cases of human infection with the H5N1 avian influenza virus. A 9-year-old female from Riau Province developed symptoms on 7 November and was hospitalized on 12 November. She recovered and was discharged from hospital on 27 November. Laboratory tests confirmed the presence of the H5N1 avian influenza virus. Investigations into the source of her infection indicate poultry deaths at her home on 2 November.
The second case, a 2-year-old female from East Jakarta, developed symptoms on 18 November, was hospitalized on 26 November and died on 29 November. Laboratory tests have confirmed infection with the H5N1 avian influenza virus. Initial investigations into the source of her infection suggest exposure at a live bird market.
Of the 139 cases confirmed to date in Indonesia, 113 have been fatal.
Italy: Bird Flu Aid Rejected
12/10/08 Europolitics--The European Commission decided, on 10 December, that a ?20-million aid package, which Italy had planned to grant in the form of urgent measures (purchase of poultry meat, suspension of tax payments and social security contributions, restructuring aid for operators affected) in response to the bird flu crisis in 2005, was not compatible with EU regulations on state aid in agriculture. The EU executive concluded that bird flu is a recurring phenomenon and not an exceptional event and that Italy had not provided information to justify the extent of damage caused by a 'natural disaster'.
Regional Reporting and Surveillance
Hong Kong Will Investigate Whether Bird Flu Vaccine Failed
12/10/08 Bloomberg--Hong Kong will check whether bird flu
vaccines failed or the virus mutated, after an outbreak prompted
the cull of more than 80,000 chickens.
York Chow, Hong Kong?s secretary for food and health,
ordered a ban on live poultry imports yesterday, and said more
birds will be culled if the H5 avian influenza is found elsewhere.
?According to the facts received, there are also chickens
with vaccinations affected,? according to the transcript of
Chow?s remarks distributed today. ?So we have to investigate on
both, whether the virus has changed or whether the vaccination
has changed the immunity of them.?
Chow yesterday raised Hong Kong?s bird-flu alert level, and
warned citizens to take care to prevent the disease.
In June, Hong Kong ordered the slaughter of chickens in
local markets and offered to buy back licenses from poultry
farmers and traders after the deadly H5N1 bird flu strain was
discovered. Hong Kong also halted live chicken sales. That ban
was lifted in July.
Hong Kong culled its entire chicken population in 1997 after
a bird-flu outbreak.
Pandemic Preparedness
Economy puts emergency readiness in peril
12/10/08 USA Today-- The economic crisis is jeopardizing the nation's ability to handle public-health emergencies and possible bioterrorist attacks, according to government leaders and a new report.
Federal and state governments are cutting programs that help communities respond to disease outbreaks, natural disasters and bioterrorism incidents, and that "could lead to a disaster for the nation's disaster preparedness," a report released Tuesday warns.
"The economic crisis could result in a serious rollback of the progress we've made since Sept. 11," 2001, said Jeffrey Levi, executive director of the Trust for America's Health, a non-partisan research group. Federal funds are down, 11 states have already cut public-health budgets, and more could follow as the economic crisis worsens.
If emergency medical supplies are not maintained or if hospitals can't handle a huge influx of patients, the result will be more deaths and illnesses, Levi said.
Homeland Security Secretary Michael Chertoff underscored the concerns in an interview Tuesday with USA TODAY editors and reporters. His top concern, Chertoff said, is a "mass event: a big outbreak of plague or some other kind of biological weapon or a nuclear explosion."
"That's the area where the most work needs to be done," said Chertoff, who leaves the post next month. "If we don't consistently invest, we will have a problem."
Chertoff said it's difficult for government and private agencies to spend money to prepare for major attacks "because you're asking people to invest in something that they haven't seen yet ? or haven't seen since the anthrax attacks of 2001. Therefore, it seems less urgent than, how do we repair the schools today."
The economic crisis in the USA could undo years of investment, planning and research, the trust said.
In its sixth annual report card rating how well states are prepared to handle health emergencies, the group said "significant progress" has been made since the federal government began giving states and hospitals billions of dollars in 2002.
All 50 states now have a good plan to distribute emergency vaccines, antidotes and medications from federal stockpiles in an emergency, the trust said. In 2005, only seven states had good plans, the trust said.
Richard Besser, the physician who heads the office of terrorism and emergency response at the federal Centers for Disease Control and Prevention, said "incredible accomplishments" have been made equipping states and communities to better handle health disasters. The CDC has given states $6.3 billion in grants. Besser said he shares the trust's concerns "that we could see a decline in the systems that we have built" and echoed the trust's call for more federal funds.
Even with the improvement, preparation varies widely from state to state. The trust says 34 states have bought adequate supplies of antiviral drugs to combat a flu pandemic. But 16 state supplies are inadequate, and some ? such as Colorado, Florida and Maine ? have minimal doses to give to their residents.
"Where you live will determine whether or not you will survive a flu pandemic," Levi said. He said the federal government should set standards for state emergency health preparation.
The trust also wants states to enact laws that limit the legal liability of businesses, non-profit organizations and health care workers that volunteer to help during a health emergency.
The trust gives the highest rating on preparation to Louisiana, New Hampshire, North Carolina, Virginia and Wisconsin.
The lowest ratings went to Arizona, Connecticut, Florida, Maryland, Montana and Nebraska.
Quid Novi
Hong Kong begins mass cull of birds at market, screens virus
12/10/08 Reuters--Health workers in masks culled tens of thousands of chickens in Hong Kong on Wednesday, a day after authorities raised the bird flu alert level to "serious" following a H5 bird flu outbreak at a farm.
[link to press photo]
Health workers pack dead chicken at a wholesale poultry market in Hong Kong December 10, 2008. Health workers clad in masks began culling thousands of chickens at a markeplace in Hong Kong on Wednesday, a day after authorities raised the bird flu alert level to "serious" following an outbreak at a farm. (REUTERS/Woody Wu)
The outbreak near the border with China was the city's first in five years despite mass vaccination of the birds, prompting concerns that the virus might have mutated.
"Viruses change and since 1997, it has been changing. If we have been using the same vaccine since 2003, its efficacy would not be the same," Ho Pak-leung, a microbiologist at the University of Hong Kong, told Reuters in an interview.
Laboratories in the city were trying to determine the precise identity of the H5 virus that caused the farm outbreak.
Another expert said it was likely to turn out to be the highly pathogenic H5N1 strain, which crops up regularly in flocks in Asia, parts of Europe and Africa.
Although H5N1 is mainly a disease among birds, it may mutate into a form that spreads easily among people. If that happens, it could trigger a pandemic and kill millions. Even in its current hard-to-catch form, H5N1 has infected 389 people since 2003, killing 246 of them.
Ho said scientists would be able to establish within a week if there were changes or characteristics in the virus that may allow it to spread easily among people.
"Genetic sequencing is being done. The key is whether it is still a fully avian virus," Ho said.
Scientists Hong Kong and mainland China are studying if new vaccines are needed to protect chickens against H5N1.
"If the study suggests that a new vaccine may provide better protection for chickens, we will select some to try out for a test trial of the new vaccine," Health Secretary York Chow said.
Workers clad in masks, white medical suits and black rubber gloves began the culling in a wholesale market on Wednesday. Culling also continued for the second day in areas within a 3 km radius of the infected farm.
By late afternoon, some 48,000 chickens had been killed, a government spokeswoman said, out of a total 80,000 birds that are meant to be culled.
China's southern Guangdong province has suspended all live poultry shipments to Hong Kong for 21 days to prevent any spread of the virus, China's official Xinhua news agency said, citing an official at the Guangdong Provincial Administration of Quality Supervision, Inspection and Quarantine.
Hong Kong told China that some 100 breeding and sentinel chickens died on Sunday at the Hong Kong poultry farm, where 60,000 chickens were being raised, the Xinhua report said.
Sentinel chickens are deliberately left unvaccinated for the purpose of providing early warning signs of viruses in the environment. Hong Kong has been using this method since 2003.
Vaccines
Dressed to Kill: From Virus to Vaccine
12/11/08 Physorg.com--In a pioneering effort, researchers at the National Institute of Standards and Technology and the University of Queensland in Australia have successfully demonstrated that they can count, size and gauge the quality of virus-like particle-based (VLP) vaccines much more quickly and accurately than previously possible. Their findings could reduce the time it takes to produce a vaccine from months to weeks, allowing a much more agile and effective response to potential outbreaks.
Viruses are small, simple bodies consisting of DNA or RNA wrapped in a protein shell studded with short strands of protein. Viruses use these short strands of protein like a skeleton key to unlock and invade healthy cells, replace their DNA, hijack the cells? replication machinery and turn them into virus-producing factories. As with smallpox and influenza, the only way to combat the virus is through vaccination, in which dead or weakened viruses are injected into the body. Unable to cause any real harm, the dead or weakened viruses allow the body to develop antigens that can fight off the infection in the future.
?The problem with this approach is that it takes a long time to develop vaccines because viruses have to be grown in chicken eggs or cell culture, which can take months,? said Leonard Pease, a NIST researcher working on the project. ?In the case of new diseases, such as bird flu, which spread very rapidly, thousands or even millions of people could become infected and die in the time it takes to produce an effective vaccine.?
In order to speed the creation and delivery of these life-saving treatments, scientists at NIST and the University of Queensland in Australia are working to develop a new class of vaccines with virus-like particles (VLP). First used in the cervical cancer vaccine, VLP-based vaccines consist of an artificial protein shell that has been coated with proteins specific to whatever disease the vaccine is intended to control. Although the VLP is dressed up to look like the real thing to the body?s immune system, it contains no DNA or RNA and is incapable of causing infection. Because VLPs do not have to be grown, vaccines based on these particles can be deployed much faster than traditional vaccines.
Whether or not a VLP-based vaccine will be effective depends on whether the VLPs are well-formed and properly coated. Electrospray differential mobility analysis (ES-DMA) is a particle sizing technique able to count millions of particles an hour with subnanometer resolution. NIST researcher Leonard Pease and his team were able to determine that well-formed VLPs that have been coated with bird flu proteins are 2 nanometers larger than those without, a critical step towards the creation of future bird flu vaccines. The team verified their results using a number of other highly accurate, but much slower, particle sizing methods. This experiment marked the first time that ES-DMA has been used to characterize VLPs, though researchers at NIST have also shown the technique to be useful for other biological applications (See ?NIST Trumps the Clumps: Making Biologic Drugs Safer?.)
NIST scientists plan to adapt the technique as a means of creating virus filter testing solutions in collaboration with virus filter manufacturers to ensure vaccines given to the public meet Food and Drug Administration safety standards.
Reference: L.F. Pease III, D.I. Lipin, D-H. Tsai, M.R. Zachariah, L.H.L. Lua, M.J. Tarlov and A.P.J. Middelberg. Quantitative characterization of virus-like particles by asymmetrical flow field flow Fractionation, electrospray differential mobility analysis, and transmission electron microscopy (http://dx.doi.org/10.1002/bit.22085). Biotechnology and Bioengineering. Published Online: Aug. 18, 2008.
